Field of Invention
The invention relates to radio frequency technology, in particular, to voltage controlled oscillator (VCO) based on hybrid resonator.
Background of Invention
A voltage controlled oscillator (VCO) is one of the key components of Radio Frequency (RF) and microwave devices, which often consists of a negative resistance circuit and a resonant circuit. Traditionally the resonant circuit is LC series resonator having an inductor and a capacitor put in series, in which one end of the LC resonator is connected to the negative resistance circuit, and the other end is grounded. Since the quality factor (Q value) of the resonator normally decreases as the increase of tuning frequency, the phase noise of VCO normally gets worse with the increase of tuning frequency while in use. Therefore, how to design a VCO that is able to maintain low phase noise at higher tuning frequency has become a well-known issue. However, there is no corresponding device available and no related invention from prior art that can effectively resolve such issue.